Degradation mechanism of decabromodiphenyl ethers was studied by gas chromatography-mass spectrometry（GC-MS）.Effects of storage time,storage temperature,light and concentration of decabromodiphenyl ethers on the degradation proccess of decabromodiphenyl ethers were evaluated,and the degradation products were detected.The results showed that the decabromodiphenyl ethers were degraded as the storage time extended at ambient temperature.The degradation rate was rapid, and 848% decabromodiphenyl ethers were degraded in 10 h when they were exposed to ultraviolet rays.The major degradation mechanism of decabromodiphenyl ethers were debromination,and the degradation products were the following potentially toxic compounds:nonabromodiphenyl ethers,octabromodiphenyl ethers,heptabromodiphenyl ethers,hexabromodiphenyl ethers and pentabromodiphenyl ethers.This study can provide a scientific guidance for determination of decabromodiphenyl ethers in electrical and electronic equipments.